This invention relates to an electromagnetic deflection in-line electron gun type colour picture tube device having a deflection yoke device mounted on a joint neck and funnel portion of a colour picture tube.
Conventionally, a self-convergence type colour picture tube device has been known which includes a colour picture tube with three electron guns arranged in line in the horizontal deflection direction and a deflection yoke device mounted to the colour picture tube for generating an astigmatism correcting magnetic field consisting of the horizontal deflection magnetic field in the form of a pincushion and the vertical deflection magnetic field in the form of a barrel. In this type, when the astigmatism correcting magnetic field of this deflection yoke device is selected such that the convergence of three electron beams are optimum over the entire phosphor screen, the landing adjustment of the electron beams is accomplished by only adjusting static convergence on the central portion of the picture screen resulting in that a dynamic convergence adjusting circuit is not necessary at all, which has been necessary in a prior art colour picture tube of three electron guns arranged in a delta configuration.
In one example of a prior art colour picture tube device of this type, as will be explained referring to the accompanying drawings hereinafter, a deflection yoke having a considerably larger inner diameter than the outer diameter of the funnel and neck portion of colour picture tube is employed and this deflection yoke is fixedly mounted to the colour picture tube in such a manner that a yoke ring which is integral with the deflection yoke is bonded by using hotmelt type bonding material such as for example polyamide resin to the supporting columns of the funnel ring bonded to the funnel portion after adjustment of the location of the deflection yoke against the colour picture tube has been completed.
With this construction, however, there has been a disadvantage of requiring a long manufacturing time due to the fact that it takes about 5 to 7 minutes for the hotmelt type bonding material to harden, which bonding material has been applied to the yoke ring integral with the deflection yoke after adjusting the location of the deflection yoke. Furthermore, there has been a difficulty for reliable fixation since the deflection yoke is bonded to only the funnel portion with a relatively large gap maintained between the deflection yoke and the neck portion so that the deflection yoke is fixed to the funnel portion in a cantilever fashion, thereby resulting in peeling off or dislocation.